We're learning more about how thieves are using all that credit card information stolen from target. A large number of the 40 million cards are now being sold on the black market. This, as investigators step up their efforts. And target launches a big p.R. Blitz aimed at understandably angry customers. Reena ninan is all over the story this morning. Reporter: Good morning. I haven't even started my christmas shopping yet. Really? Reporter: No. This is one of the worst weekends to hear about this. If you think there aren't any fraud charges on my card, I many u.S. Be in the clear, authorities say the stolen target cards may be among the millions being swiped in the final christmas shopping crush. Four days before christmas, credit card theft alert. Abc news has learned face cards with credit card numbers stolen from target's recent data breach are now flooding the black market. They're just worldwide and are distributed through organized crime. Reporter: New york police forces telling abc news, the stolen card information is selling in batches of 1 million cards at a time. Once the information is stolen, they work globely with other cyber thieves who distribute the cards who turn data into money. Reporter: A charge at walgreens tipped her off to fraud on her card. I didn't go to walgreens. I would never spend $250 in walgreens. That got my attention. Reporter: How does the stolen data get into the black market? It's surprisingly similar to the setup in "identity thieves." It's like getting a new room key at a hotel front desk, they swipe it on a blank card. Your credit card, now, can be used anywhere. It's devastating. It's scary knowing, well, if they have my information, who else got it? Reporter: The new york police department retrieved 39 gift card bonus card numbers in an arrest on thursday. Those account numbers right now being run through the secret service data base to see if they match the stolen target cards. The new york attorney general's aftering three credit checks for new york residents. And tar go knows this is a p.R. Disaster. They're giving credit checks to everyone on saturday and sunday. Someone has to eat the fraud charges. And one thing credit card companies do is jack up the interest rates. Ultimately, it comes back to the consumers. I'm sorry. Your christmas gift will be late from me. You better get shopping, right now. I'm going, after the show. This couldn't have happened at a worse time of the year for target. We're going to turn to

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